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ABSTRACT Grain hardness (GH) plays an important role in wheat quality evaluation. Identification of new genes or quantitative trait loci (QTL) for GH is an effective strategy for wheat quality breeding. Here, we used a recombinant inbred line (RIL) population derived from a cross between two hard wheat Yangmai 4 (YM4) and Yanzhan 1 (YZ1) to identify QTL for GH. No QTL was detected on 5D chromosome, as parents YM4 and YZ1 possessed the two hard alleles Pinb‐D1b and Pinb‐D1p at the Hardness‐5D (Ha‐5D) locus, respectively. A total of three GH QTL were identified, among which QGh.yaas‐4B and QGh.yaas‐7D could be detected in all experiments and for mean value, explaining 8.69%–15.07% of the phenotypic variances. QGh.yaas‐4D, co‐located with Rht‐D1, was detected in one experiment and for mean value, explaining 9.94%–11.39% of the phenotypic variances. We were not able to precisely validate QGh.yaas‐4B due to its large mapping interval. Kompetitive allele‐specific PCR (KASP) markers for QGh.yaas‐7D were successfully developed, and then QGh.yaas‐4D and QGh.yaas‐7D were validated in a panel of 101 wheat cultivars/lines (all carrying Pina‐D1a and Pinb‐D1a alleles). Cultivars/lines harbouring the positive alleles of QGh.yaas‐4D and QGh.yaas‐7D increased GH by 85.16% relative to the ones without any positive allele. These results provide new loci and resources in molecular breeding for wheat hardness. [ABSTRACT FROM AUTHOR]

ABSTRACT Septoria nodorum blotch (SNB) is a fungal disease of wheat caused by the necrotrophic fungus Parastagonospora nodorum (Berk.), considered as one of the most devastating fungal diseases affecting winter wheat (Triticum aestivum L.). The complex inheritance of resistance to SNB poses significant challenges to breeding programmes. Improving selection precision and identifying novel resistance QTLs are crucial for enhancing SNB resistance. This study investigated strategies for crop genetic improvement, including genome‐wide association mapping (GWAS) and genomic prediction (GP), within a practical breeding programme. A population of 1500 winter wheat breeding lines was phenotyped for SNB resistance over 5 years across 19 geographical locations under natural infection conditions. Despite highly unbalanced breeder's data, medium to high heritabilities for SNB resistance were achieved. GWAS identified 11 significant marker‐trait associations for SNB resistance across Chromosomes 2A, 2B, 4B, 4D, 5D and 7B. GP fivefold cross‐validation analysis revealed a predictive ability of 0.52 for SNB resistance. The resistant wheat genotypes and SNP markers identified in this study will be valuable assets for future breeding efforts to enhance SNB resistance in wheat. [ABSTRACT FROM AUTHOR]

Low temperature chilling is one of the major abiotic stresses affecting growth and yield of Triticum aestivum L. With global climate change, the risk of cold damage in wheat production has increased. In recent years, with the extensive research on wheat chilling resistance, especially the development of genetic engineering technology, the research on wheat chilling resistance has made great progress. This paper describes the mechanism of wheat cold damage, including cell membrane injury, cytoplasmic concentration increased as well as the imbalance of the ROS system. Mechanisms of cold resistance in wheat are summarised, including hormone signalling, transcription factor regulation, and the role of protective enzymes of the ROS system in cold resistanc. Functions of cloned wheat cold resistance genes are summarised, which will provide a reference for researchers to further understand and make use of cold resistance related genes in wheat. The current cold resistant breeding of wheat relies on the agronomic traits and observable indicators, molecular methods are lacked. A strategy for wheat cold-resistant breeding based on QTLs and gene technologies is proposed, with a view to breeding more cold-resistant varieties of wheat with the deepening of the research. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Can modern breeding technologies, such as genome editing, contribute to reduced pesticide usage? This question has been accentuated by a recent legal proposal to exempt genome‐edited plants from the strict regulations applied to classical genetically modified (GM) crops within the European Union (EU). Using official statistics on crop cultivation and pesticide usage for two example crops commonly grown in Sweden, we calculate that cereal farmers collectively could save up to 70 million € in pesticide usage for wheat alone and that a late blight‐resistant potato could reduce pesticide usage by over 80% provided that the EU legislation is amended. Summary: The European Commission has set goals to reduce the use of chemical pesticides, and one way to meet these goals in the agricultural sector is to breed disease‐resistant crops. Here, we ask whether modern breeding technologies, for example, genome editing using site‐directed nucleases, can contribute to these goals. This question has been accentuated by recent legal proposals in the European Union (EU) and several other jurisdictions worldwide to exempt genome‐edited plants from the strict regulations often applied to classical genetically modified (GM) crops. Using official statistics on crop cultivation and pesticide usage for two example crops commonly grown in Sweden (wheat and potato), we show that cereal farmers collectively could potentially save up to 70 million € in pesticide usage for wheat alone and that a late blight‐resistant potato could reduce pesticide usage by over 80% provided that the EU legislation is amended. Given the immense potential of genome‐edited crops, we further discuss details in the legal proposal currently being negotiated in the EU on the so‐called new genomic techniques that includes both genome editing and targeted insertions of cisgenes. Although promising, we argue that several technical limitations in the legal proposal will, if implemented, hamper the development of disease‐resistant crops and make the suggested legislation less future‐proof. [ABSTRACT FROM AUTHOR]

Background: Fusarium head blight (FHB), a devastating disease of wheat production, is predominantly elicited by Fusarium graminearum (Fg). The tetraploid Thinopyrum elongatum is a tertiary gene resource of common wheat that possesses high affinity and displays high resistance traits against multiple biotic and abiotic stress. We aim to employ and utilize the novel FHB resistance resources from the wild germplasm of common wheat for breeding. Results: Durum wheat-tetraploid Th. elongatum amphiploid 8801 was hybridized with common wheat cultivars SM482 and SM51, and the F5 generation was generated. We conducted cytogenetically in situ hybridization (ISH) technologies to select and confirm a genetically stable 7E(7D) substitution line K17-1069-5, which showed FHB expansion resistance in both field and greenhouse infection experiments and displayed no significant disadvantage in agronomic traits compared to their common wheat parents in the field. The F2 segregation populations (K17-1069-5 × SM830) showed that the 7E chromosome conferred dominant FHB resistance with dosage effect. We developed 19 SSR molecular markers specific to chromosome 7E, which could be conducted for genetic mapping and large breeding populations marker-assisted selection (MAS) during selection procedures in the future. We isolated a novel Fhb7 allele from the tetraploid Th. elongatum chromosome 7E (Chr7E) using homology-based cloning, which was designated as TTE7E-Fhb7. Conclusions: In summary, our study developed a novel wheat-tetraploid Thinopyrum elongatum 7E(7D) K17-1069-5 substitution line which contains stable FHB resistance. [ABSTRACT FROM AUTHOR]

Rapid urbanization and evolving dietary preferences have heightened the demand for durum wheat and its derivatives in developing nations like Nepal. This study represents the first comprehensive exploration and evaluation of durum wheat genotypes in Nepal, addressing the escalating need for highyielding varieties. The primary objective was to identify stable and prolific durum wheat lines for release, enhancing Nepal's durum wheat breeding program. Utilizing genotypes from CIMMYT's disease screening and yield nurseries from 2011/12 to 2020/21, a total of 132 genotypes, including international checks, underwent evaluation over ten years under the Alpha Lattice design. Results revealed significant variation among genotypes for grain yield and other traits, identifying high-yielding and stable lines suitable for Nepal. Heritability analysis highlighted moderate heritability for grain number per spike, thousand-grain weight, and grain yield. Cluster analysis identified distinct clusters with high grain yield and desirable agronomic traits. Disease incidence facilitated the selection of resistant lines, with DWK38 emerging as the highest grain yielder (4416.04 kg/ha). Overall, durum wheat lines from CIMMYT exhibited robust performance in Nepal, enabling the identification of superior lines with potential benefits for farmers and consumers. The study's implications include developing and releasing superior durum lines in Nepal, providing farmers with profitable alternatives amidst evolving food habits. In conclusion, the findings from this study provide a valuable foundation for future durum wheat breeding efforts in Nepal, guiding the selection of genotypes that are well-suited to the diverse environmental challenges of the region. [ABSTRACT FROM AUTHOR]

The root architecture, more seminal roots, and Deeper roots help the plants to uptake the resources from the deeper soil layer to ensure better growth. The Gibberellic acid-sensitive (GA-sensitive) Rht genes are well known for increasing drought tolerance in wheat. Much work has been performed on the effect of these genes on the plant agronomic traits and little work has been done on the effect of Rht genes on seminal roots and root architecture. This study was designed to evaluate 200 wheat genotypes under normal and osmotic stress. The genotypes were sown in the solution culture and laid under CRD factorial arrangement with three replications and two factors i.e., genotypes and treatments viz. normal and osmotic stress (20% PEG-6000) applied one week after germination. The data was recorded for the root traits. Results demonstrated that out of 200 genotypes, the GA-sensitive Rht13 gene was amplified in 21 genotypes with a fragment length of 1089 bp. In comparison, the GA-insensitive Rht1 gene was amplified in 24 genotypes with a band size of 228 bp. From 200 wheat genotypes, 122 genotypes produced 5 seminal roots, 4 genotypes 4 seminal roots, and 74 genotypes 3 seminal roots. The genotypes G-3 (EBW11TALL#1/WESTONIA-Rht5//QUAIU#1), G-6 (EBW01TALL#1/SILVERSTAR-Rht13B//ROLF07) and G-8 (EBW01TALL#1/SILVERSTAR-Rht13B//NAVJ07) produced 5 seminal roots and have longer coleoptile (> 4.0 cm), root (> 11.0 cm) and shoot (> 17 cm) under normal and osmotic stress. Furthermore, Ujala 16, Galaxy-13, and Fareed-06 produced 3 seminal roots and have short coleoptile (< 3 cm), root (< 9.0 cm) and shoot (< 10.0 cm). These results showed that the genotypes showing the presence of GA-sensitive Rht genes produced a greater number of seminal roots, increased root/shoot growth, and osmotic stress tolerance compared to the genotypes having GA-insensitive Rht genes. Thus, the Rht13 gene improved the root architecture which will help to uptake the nutrients from deeper soil layers. Utilization of Rht13 in wheat breeding has the potential to improve osmotic stress tolerance in wheat. [ABSTRACT FROM AUTHOR]

Powdery mildew (PM) poses an extreme threat to wheat yields and quality. In this study, 262 recombinant inbred lines (RILs) of Doumai and Shi 4185 cross were used to map PM resistance genes across four environments. High-density genetic linkage map of the Doumai/Shi 4185 RIL population was constructed using the wheat Illumina iSelect 90K single-nucleotide polymorphism (SNP) array. In total, four stable quantitative trait loci (QTLs) for PM resistance, QPm.caas-2AS, QPm.caas-4AS, QPm.caas-4BL, and QPm.caas-6BS, were detected and explained 5.6%-15.6% of the phenotypic variances. Doumai contributed all the resistance alleles of QPm.caas-2AS, QPm.caas-4AS, QPm.caas-4BL, and QPm.caas-6BS. Among these, QPm.caas-4AS and QPm.caas-6BS overlapped with the previously reported loci, whereas QPm.caas-2AS and QPm.caas-4BL are potentially novel. In addition, six highconfidence genes encoding the NBS-LRR-like resistance protein, disease resistance protein family, and calcium/calmodulin-dependent serine/threonine-kinase were selected as the candidate genes for PM resistance. Three kompetitive allele-specific PCR (KASP) markers, Kasp_PMR_2AS for QPm.caas-2AS, Kasp_PMR_4BL for QPm.caas-4BL, and Kasp_PMR_6BS for QPm.caas-6BS, were developed, and their genetic effects were validated in a natural population including 100 cultivars. These findings will offer valuable QTLs and available KASP markers to enhance wheat marker-assisted breeding for PM resistance. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) is a devastating disease of wheat, causing yield losses, reduced grain quality, and mycotoxin contamination. Breeding can mitigate the severity of FHB epidemics, especially with genomics-assisted methods. The mechanisms underlying resistance to FHB in wheat have been extensively studied, including phenological traits and genome-wide markers associated with FHB severity. Here, we aimed to improve genomic prediction for FHB resistance across breeding programs by incorporating FHB-correlated traits and FHB-associated loci as model covariates. We combined phenotypic data on FHB severity, anthesis date, and plant height with genome-wide marker data from five Central European winter wheat breeding programs for genome-wide association studies (GWAS) and genomic prediction. Within all populations, FHB was correlated with anthesis date and/or plant height, and a marker linked to the semi-dwarfing locus Rht-D1 was detected with GWAS for FHB. Including the Rht-D1 marker, anthesis date, and/or plant height as covariates in genomic prediction modeling improved prediction accuracy not only within populations but also in cross-population scenarios. [ABSTRACT FROM AUTHOR]

Summary: Meiotic crossovers (COs) generate genetic diversity and are crucial for viable gamete production. Plant COs are typically limited to 1–3 per chromosome pair, constraining the development of improved varieties, which in wheat is exacerbated by an extreme distal localisation bias. Advances in wheat genomics and related technologies provide new opportunities to investigate, and possibly modify, recombination in this important crop species. Here, we investigate the disruption of FIGL1 in tetraploid and hexaploid wheat as a potential strategy for modifying CO frequency/position.We analysed figl1 mutants and virus‐induced gene silencing lines cytogenetically. Genetic mapping was performed in the hexaploid.FIGL1 prevents abnormal meiotic chromosome associations/fragmentation in both ploidies. It suppresses class II COs in the tetraploid such that CO/chiasma frequency increased 2.1‐fold in a figl1 msh5 quadruple mutant compared with a msh5 double mutant. It does not appear to affect class I COs based on HEI10 foci counts in a hexaploid figl1 triple mutant. Genetic mapping in the triple mutant suggested no significant overall increase in total recombination across examined intervals but revealed large increases in specific individual intervals.Notably, the tetraploid figl1 double mutant was sterile but the hexaploid triple mutant was moderately fertile, indicating potential utility for wheat breeding. See also the Commentary on this article by Phillips & Lloyd, 244: 341–343. [ABSTRACT FROM AUTHOR]

In response to the escalating challenges posed by unpredictable environmental conditions, the pursuit of early maturation in bread wheat has emerged as a paramount research endeavor. This comprehensive review delves into the multifaceted landscape of strategies and implications surrounding the unlocking of early maturation in bread wheat varieties. Drawing upon a synthesis of cutting-edge research in genetics, physiology, and environmental science, this review elucidates the intricate mechanisms underlying early maturation and its potential ramifications for wheat cultivation in dynamic environments. By meticulously analyzing the genetic determinants, physiological processes, and environmental interactions shaping early maturation, this review offers valuable insights into the complexities of this trait and its relevance in contemporary wheat breeding programs. Furthermore, this review critically evaluates the trade-offs inherent in pursuing early maturation, navigating the delicate balance between accelerated development and optimal yield potential. Through a meticulous examination of both challenges and opportunities, this review provides a comprehensive framework for researchers, breeders, and agricultural stakeholders to advance our understanding and utilization of early maturation in bread wheat cultivars, ultimately fostering resilience and sustainability in wheat production systems worldwide. [ABSTRACT FROM AUTHOR]

Summary: Increasing crop yield depends on selecting and utilizing pleiotropic genes/alleles to improve multiple yield‐related traits (YRTs) during crop breeding. However, synergistic improvement of YRTs is challenging due to the trade‐offs between YRTs in breeding practices. Here, the favourable haplotypes of the TaCYP78A family are identified by analysing allelic variations in 1571 wheat accessions worldwide, demonstrating the selection and utilization of pleiotropic genes to improve yield and related traits during wheat breeding. The TaCYP78A family members, including TaCYP78A3, TaCYP78A5, TaCYP78A16, and TaCYP78A17, are organ size regulators expressed in multiple organs, and their allelic variations associated with various YRTs. However, due to the trade‐offs between YRTs, knockdown or overexpression of TaCYP78A family members does not directly increase yield. Favourable haplotypes of the TaCYP78A family, namely A3/5/16/17Ap‐Hap II, optimize the expression levels of TaCYP78A3/5/16/17‐A across different wheat organs to overcome trade‐offs and improve multiple YRTs. Different favourable haplotypes have both complementary and specific functions in improving YRTs, and their aggregation in cultivars under strong artificial selection greatly increase yield, even under various planting environments and densities. These findings provide new support and valuable genetic resources for molecular breeding of wheat and other crops in the era of Breeding 4.0. [ABSTRACT FROM AUTHOR]

Cysteine-rich peptides play an important role in the plant defense system. The objective of this study was in silico searching for the genes encoding antimicrobial and signaling peptides in the genome of the tall wheatgrass Thinopyrumelongatum (Host) D.R. Dewey (2n = 14, EE), a wild cereal that is highly resistant to pathogens and abiotic stress. Bioinformatic analysis provided information for the identification in the tall wheatgrass genome of 154 novel genes coding for antimicrobial and signaling peptide precursors belonging to nine families. A number of cysteine-rich peptide genes were found to contain introns. The structure of peptide precursors and the location of the peptide genes on the wheatgrass chromosomes were determined. The highest similarity of the wheatgrass peptide sequences with homologous peptides from plants of the genera Triticum and Aegilops was demonstrated, supporting the cytogenetic data on the relatedness between genome E and genome D, as well as the genomes close to it. The data obtained contribute to the characterization of the molecular components of the Th. elongatum immune system and will serve as the basis for further studies of the mechanisms of resistance, as well as for the scientifically based practical use of this species as the resistance donor in wheat breeding. [ABSTRACT FROM AUTHOR]

Breeding high-photosynthetic-efficiency wheat varieties is a crucial link in safeguarding national food security. Traditional identification methods necessitate laborious on-site observation and measurement, consuming time and effort. Leveraging unmanned aerial vehicle (UAV) remote sensing technology to forecast photosynthetic indices opens up the potential for swiftly discerning high-photosynthetic-efficiency wheat varieties. The objective of this research is to develop a multi-stage predictive model encompassing nine photosynthetic indicators at the field scale for wheat breeding. These indices include soil and plant analyzer development (SPAD), leaf area index (LAI), net photosynthetic rate (Pn), transpiration rate (Tr), intercellular CO2 concentration (Ci), stomatal conductance (Gsw), photochemical quantum efficiency (PhiPS2), PSII reaction center excitation energy capture efficiency (Fv'/Fm'), and photochemical quenching coefficient (qP). The ultimate goal is to differentiate high-photosynthetic-efficiency wheat varieties through model-based predictions. This research gathered red, green, and blue spectrum (RGB) and multispectral (MS) images of eleven wheat varieties at the stages of jointing, heading, flowering, and filling. Vegetation indices (VIs) and texture features (TFs) were extracted as input variables. Three machine learning regression models (Support Vector Machine Regression (SVR), Random Forest (RF), and BP Neural Network (BPNN)) were employed to construct predictive models for nine photosynthetic indices across multiple growth stages. Furthermore, the research conducted principal component analysis (PCA) and membership function analysis on the predicted values of the optimal models for each indicator, established a comprehensive evaluation index for high photosynthetic efficiency, and employed cluster analysis to screen the test materials. The cluster analysis categorized the eleven varieties into three groups, with SH06144 and Yannong 188 demonstrating higher photosynthetic efficiency. The moderately efficient group comprises Liangxing 19, SH05604, SH06085, Chaomai 777, SH05292, Jimai 22, and Guigu 820, totaling seven varieties. Xinmai 916 and Jinong 114 fall into the category of lower photosynthetic efficiency, aligning closely with the results of the clustering analysis based on actual measurements. The findings suggest that employing UAV-based multi-source remote sensing technology to identify wheat varieties with high photosynthetic efficiency is feasible. The study results provide a theoretical basis for winter wheat phenotypic monitoring at the breeding field scale using UAV-based multi-source remote sensing, offering valuable insights for the advancement of smart breeding practices for high-photosynthetic-efficiency wheat varieties. [ABSTRACT FROM AUTHOR]

Context: Wheat (Triticum aestivum L.) is an important crop that provides food to millions of people all over the world. Currently, wheat production is limited due to various biotic and abiotic stresses resulting from uneven patterns of climate change. Therefore, it is very important to develop climate-resilient wheat cultivars. Crop genetic diversity allows the scientific community to identify genetic variations that can be utilised in the development of improved cultivars. Aims: This study planned to characterise the wheat germplasm with the iPBS-retrotransposons marker system. Methods: A total of 30 iPBS-retrotransposons markers were screened and among these, the 12 most polymorphic markers were selected for further analysis. Key results: Molecular characterisation yielded a total of 170 bands, of which 143 were polymorphic. A substantial level of genetic diversity was observed (mean effective number of alleles: 1.37, Shannon's information index: 0.23, gene diversity: 0.35). Maximum genetic distance was observed in G9 and G60 genotypes. Analysis of molecular variance revealed that most genetic variation (95%) occurred within the populations. The model-based structure algorithm divided the studied germplasm into three populations based on their collection regions. Similarly, the neighbour-joining analysis also divided 70 tested wheat genotypes into three populations, whereas principal coordinate analysis divided the evaluated germplasm into four populations. Conclusions: This study confirms the iPBS-retrotransposons as an ideal marker for the genetic diversity assessment studies for any crop, especially for wheat. Implications: The results presented here will be helpful for the scientific community in the marker-assisted breeding of wheat. Wheat, a vital global food source, faces production limitations due to climate-induced stresses. Developing resilient cultivars is crucial. Genetic diversity aids in identifying variations for improved cultivars. This study utilised iPBS-retrotransposons to characterise wheat germplasm, yielding 170 bands. Genetic distance highlighted G9 and G60 as genetically distinct genotypes. Different methods identified three or four distinct groups of genotypes amongst the studied germplasm. This informs targeted breeding strategies for enhanced wheat varieties. This article belongs to the Collection Plant breeding- and genetics-based tools for food security under changing climate. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) has become the most widely grown cereal crop in the Nordic-Baltic region, but due to climate change, its yields are under increasing risk. Here we present results of an international effort to use available wheat germplasm from the region to identify tools and genotypes for breeding wheat varieties with improved stability. We formed a panel of 300 spring wheat genotypes from the Nordic-Baltic region and studied their phenotypic diversity across environments to identify genotypes with high potential for adaptation to a changing climate. Field experiments were carried out in 2021 and 2022 in Estonia, Latvia, Lithuania and Norway. The performance and stability of yield (GY), protein content (PC), thousand kernel weight (TKW), test weight (TW), length of growing period (GP), and nine other traits were studied. Drought and excessive rainfall occurred in the Baltic countries in 2021–2022, whereas the weather in Norway was more stable. High variability for most traits, and significant GxE effects for all studied traits, were identified. We identified stable genotypes combining yield and quality using the AMMI model-based Weighted Average of Absolute Scores index (WAASB). Finally, we selected nineteen superior genotypes that combined high yield with high values of important quality traits. Thus, combining broad Nordic-Baltic wheat germplasm with extensive field phenotyping, we identified promising breeding material to develop climate-ready spring wheat varieties for the region. [ABSTRACT FROM AUTHOR]

Terminal heat stress is one of the major problems in wheat growth, yield and grain-quality. Here, we have developed wheat mutant (M3) for HS-tolerance and improved grain-quality using gamma irradiation [parent-MP3054- C-306/CB.SPRING BW/CPAN2072 (Parentage)]. Biochemical markers based characterization showed wheat mutant to be better in HS-tolerance and grain-quality, as compared to parent. To elucidate the mechanism of thermotolerance in wheat mutant, we performed de novo transcriptome assembly of mutant (M3), parent (P3), and mutant exposed to HS (M3H). We generated 6.3 (P3-R1), 6.6 (P3-R2), 8.1 (M3-R1), 7.1 (M3-R2), 7.6 (M3H-R1), and 6.1 (M3H-R2) million clean reads and identified 3,05,537 genes and 5,88,788 transcripts with an N50 of 1,349 bp. We observed 6,120 upregulated and 4,428 downregulated transcripts (M3 vs P3), 11,354 upregulated and 12,408 downregulated genes (M3H vs P3) and 4817 upregulated and 9085 downregulated genes (M3H vs M3). The high HS-tolerance and improved grain-quality of the wheat mutant was observed due to the upregulation of serine threonine kinase (STK), HSP20, SOD, ATP-binding cassette (ABC) transporters, heat shock transcription factor (HSF), and calcium dependent protein kinase (CDPK) and stability of starch synthase, sucrose synthase, and debranching enzyme. Gene Ontology analysis showed 'ATP-binding' to be most enriched category. The carbon assimilatory pathways (photosynthesis and starch biosynthesis) were observed most altered under terminal HS. The developed mutant can be further utilized as donor in wheat breeding program to develop 'climate-smart' crop. [ABSTRACT FROM AUTHOR]

The constantly growing need to increase the production of agricultural products in changing climatic conditions makes it necessary to accelerate the development of new cultivars that meet the modern demands of agronomists. Currently, the breeding process includes the stages of genotyping and phenotyping to optimize the selection of promising genotypes. One of the most popular phenotypic methods is the pulse-amplitude modulated (PAM) fluorometry, due to its non-invasiveness and high information content. In this review, we focused on the opportunities of using chlorophyll fluorescence (ChlF) parameters recorded using PAM fluorometry to assess the state of plants in drought and heat stress conditions and predict the economically significant traits of wheat, as one of the most important agricultural crops, and also analyzed the relationship between the ChlF parameters and genetic markers. [ABSTRACT FROM AUTHOR]

Deep learning (DL) techniques have significantly enhanced the potential for wheat head detection in recent times. The different development phases of canopy, genotype, wheat heads, and wheat head orientation provide considerable obstacles. The overlapping density of wheat heads and windinduced picture blurring complicate wheat head recognition. This study describes an effective wheat head detection and counting method. Due to its high throughput in agricultural field analysis, remote sensing phenotyping has grown in popularity. Applying DL methods for image processing and other technological advancements has increased the scope for the quantitative evaluation of various crop traits. The ability to detect and characterize wheat heads in the industry is an important part of the wheat breeding process for selecting high-yielding cultivars. The proposed method uses the Mask region-based convolutional neural network (RCNN) framework to detect and classify the wheat ears. The complete detection task is done in three steps: region proposal generation, region of interest alignment, and mask generation. The global wheat head detection (GWHD) dataset is used for the experimental analysis of the dataset. The proposed method achieved an accuracy of 95.11% on the GWHD dataset, demonstrating its effectiveness in wheat head detection and classification tasks. [ABSTRACT FROM AUTHOR]

Leaf rust (Puccinia triticina) is a common disease that causes significant yield losses in wheat. The most frequently used methods to control leaf rust are the application of fungicides and the cultivation of resistant genotypes. However, high genetic diversity and associated adaptability of pathogen populations hamper achieving durable resistance in wheat. Emerging alternatives, such as microbial priming, may represent an effective measure to stimulate plant defense mechanisms and could serve as a means of controlling a broad range of pathogens. In this study, 175 wheat genotypes were inoculated with two bacterial strains: Ensifer meliloti strain expR+ch (producing N-acyl homoserine lactone (AHL)) or transformed E. meliloti carrying the lactonase gene attM (control). In total, 21 genotypes indicated higher resistance upon bacterial AHL priming. Subsequently, the phenotypic data of 175 genotypes combined with 9917 single-nucleotide polymorphisms (SNPs) in a genome-wide association study to identify quantitative trait loci (QTLs) and associated markers for relative infection under attM and expR+ch conditions and priming efficiency using the Genome Association and Prediction Integrated Tool (GAPIT). In total, 15 QTLs for relative infection under both conditions and priming efficiency were identified on chromosomes 1A, 1B, 2A, 3A, 3B, 3D, 6A, and 6B, which may represent targets for wheat breeding for priming and leaf-rust resistance. [ABSTRACT FROM AUTHOR]

Background: Salt stress is a prominent abiotic stressor that imposes constraints on grain yield and quality across various crops, including wheat (Triticum aestivum). This study focused on assessing the genetic diversity of 20 wheat genotypes categorized as tolerant, moderately tolerant, and sensitive with three genotypes of unknown tolerance. To address salinity stress-related problems, different morpho-physiological, osmoprotectant, biochemical, yield, and grain quality-related parameters were analyzed under control (pH 8.0, EC 3.9) and saline-sodic (pH 9.4, EC 4.02) conditions in field. Results: Findings revealed noteworthy variations among the genotypes in response to salinity stress. Greater accumulation of Na+ and lower K+ content were observed in response to salt stress in the sensitive varieties HD1941 and K9162. Proline, a stress indicator, exhibited significantly (p ≤ 0.05) greater accumulation in response to salinity stress, particularly in the tolerant cultivars KRL210 and KH65. Salt stress induced the most significant decrease (p ≤ 0.05) in spike length, thousand-grain weight, and hectolitre weight coupled with increased protein content in sensitive varieties, resulting in diminished yield. Conclusion: Correlation analysis of parameters under salinity stress showed that SOD, proline, and K+ contents can be used as the most efficient screening criteria for salinity stress during early developmental stages. Principal component analysis revealed that DBW187, DBW303, and DBW222 varieties were tolerant to salinity stress and exhibited an effective antioxidant system against salinity. This study will facilitate salt-tolerant wheat breeding in terms of the identification of tolerant lines by screening for limited traits in a wide range of germplasms. [ABSTRACT FROM AUTHOR]

Cultivated and wild species of the genus rye (Secale) are important but underexploited gene sources for increasing the genetic diversity of bread wheat. Gene transfer is possible via bridge genetic materials derived from intergeneric hybrids. During this process, it is essential to precisely identify the rye chromatin in the wheat genetic background. In the present study, backcross generation BC2F8 from a cross between Triticum aestivum (Mv9kr1) and S. cereanum ('Kriszta,' a cultivar from the artificial hybrid of S. cereale and S. strictum) was screened using in-situ hybridization (GISH and FISH) and analyzed by DArTseq genotyping in order to select potentially agronomically useful genotypes for prebreeding purposes. Of the 329,267 high-quality short sequence reads generated, 27,822 SilicoDArT and 8,842 SNP markers specific to S. cereanum 1R-7R chromosomes were identified. Heatmaps of the marker densities along the 'Lo7' rye reference pseudomolecules revealed subtle differences between the FISH- and DArTseq-based results. This study demonstrates that the "exotic" rye chromatin of S. cereanum introgressed into wheat can be reliably identified by high-throughput DArTseq genotyping. The Mv9kr1-'Kriszta' addition and translocation lines presented here may serve as valuable prebreeding genetic materials for the development of stress-tolerant or disease-resistant wheat varieties. [ABSTRACT FROM AUTHOR]

This study evaluated 290 recombinant inbred lines (RILs) of the nested association mapping (NAM) population from the UK. The population derived from 24 families, where a common parent was "Paragon," one of the UK's spring wheat cultivar standards. All genotypes were tested in two regions of Kazakhstan at the Kazakh Research Institute of Agriculture and Plant Industry (KRIAPI, Almaty region, Southeast Kazakhstan, 2019–2022 years) and Alexandr Barayev Scientific-Production Center for Grain Farming (SPCGF, Shortandy, Akmola region, Northern Kazakhstan, 2019–2022 years). The studied traits consisted of plant adaptation-related traits, including heading date (HD, days), seed maturation date (SMD, days), plant height (PH, cm), and peduncle length (PL, cm). In addition, the yield per m2 was analyzed in both regions. Based on a field evaluation of the population in northern and southeastern Kazakhstan and using 10,448 polymorphic SNP (single-nucleotide polymorphism) markers, the genome-wide association study (GWAS) allowed for detecting 74 QTLs in four studied agronomic traits (HD, SMD, PH, and PL). The literature survey suggested that 16 of the 74 QTLs identified in our study had also been detected in previous QTL mapping studies and GWASs for all studied traits. The results will be used for further studies related to the adaptation and productivity of wheat in breeding projects for higher grain productivity. [ABSTRACT FROM AUTHOR]

Environmental stresses, including drought stress, seriously threaten food security. Previous studies reported that wheat F-box protein, TaFBA1, responds to abiotic stresses in tobacco. Here, we generated transgenic wheat with enhanced (overexpression, OE) or suppressed (RNA interference, RNAi) expression of TaFBA1. The TaFBA1-OE seedlings showed enhanced drought tolerance, as measured by survival rate and fresh weight under severe drought stress, whereas the RNAi plants showed the opposite phenotype. Furthermore, the OE plants had stronger antioxidant capacity compared to WT and RNAi plants and maintained stomatal opening, which resulted in higher water loss under drought stress. However, stronger water absorption capacity in OE roots contributed to higher relative water contents in leaves under drought stress. Moreover, the postponed stomatal closure in OE lines helped to maintain photosynthesis machinery to produce more photoassimilate and ultimately larger seed size. Transcriptomic analyses conducted on WT and OE plants showed that genes involved in antioxidant, fatty acid and lipid metabolism and cellulose synthesis were significantly induced by drought stress in the leaves of OE lines. Together, our studies determined that the F-box protein TaFBA1 modulated drought tolerance and affected yield in wheat and the TaFBA1 gene could provide a desirable target for further breeding of wheat. [ABSTRACT FROM AUTHOR]

Background: Septoria tritici blotch (STB) disease causes yield losses of up to 50 per cent in susceptible wheat cultivars and can reduce wheat production. In this study, genomic architecture for adult-plant STB resistance in a Septoria Association Mapping Panel (SAMP) having 181 accessions and genomic regions governing STB resistance in a South Asian wheat panel were looked for. Results: Field experiments during the period from 2019 to 2021 revealed those certain accessions, namely BGD52 (CHIR7/ANB//CHIR1), BGD54 (CHIR7/ANB//CHIR1), IND92 (WH 1218), IND8 (DBW 168), and IND75 (PBW 800), exhibited a high level of resistance. Genetic analysis revealed the presence of 21 stable quantitative trait nucleotides (QTNs) associated with resistance to STB (Septoria tritici blotch) on all wheat chromosomes, except for 2D, 3A, 3D, 4A, 4D, 5D, 6B, 6D, and 7A. These QTNs were predominantly located in chromosome regions previously identified as associated with STB resistance. Three Quantitative Trait Loci (QTNs) were found to have significant phenotypic effects in field evaluations. These QTNs are Q.STB.5A.1, Q.STB.5B.1, and Q.STB.5B.3. Furthermore, it is possible that the QTNs located on chromosomes 1A (Q.STB.1A.1), 2A (Q.STB_DH.2A.1, Q.STB.2A.3), 2B (Q.STB.2B.4), 5A (Q.STB.5A.1, Q.STB.5A.2), and 7B (Q.STB.7B.2) could potentially be new genetic regions associated with resistance. Conclusion: Our findings demonstrate the importance of Asian bread wheat as a source of STB resistance alleles and novel stable QTNs for wheat breeding programs aiming to develop long-lasting and wide-ranging resistance to Zymoseptoria tritici in wheat cultivars. [ABSTRACT FROM AUTHOR]

Background: Wheat (Triticum aestivum L.) is an important grain crops in the world, and its growth and development in different stages is seriously affected by saline-alkali stress, especially in seedling stage. Therefore, nondestructive detection of wheat seedlings under saline-alkali stress can provide more comprehensive technical support for wheat breeding, cultivation and management. Results: This research focused on moisture signal prediction and classification of saline-alkali stress in wheat seedlings using fusion techniques. After collecting and analyzing transverse relaxation time and Multispectral imaging (MSI) information of wheat seedlings, four regression models were used to predict the moisture signal. K-Nearest Neighbor (KNN) and Gaussian-Naïve Bayes (GNB) models were combined with fivefold cross validation to classify the prediction of wheat seedling stress. The results showed that wheat seedlings would increase the bound water content through a certain mechanism to enhance their saline-alkali stress. Under the same Na concentration, the effect of alkali stress on moisture, growth and spectrum of wheat seedlings is stronger than salt stress. The Gradient Boosting Decision Regression Tree model performs the best in predicting wheat moisture signals, with a coefficient of determination (R2P) of 0.98 and a root mean square error of 109.60. It also had a short training time (1.48 s) and an efficient prediction speed (1300 obs/s). The KNN and GNB demonstrated significantly enhanced predictive performance when classifying the fused dataset, compared to using single datasets individually. In particular, the GNB model performing best on the fused dataset, with Precision, Recall, Accuracy, and F1-score of 90.30, 88.89%, 88.90%, and 0.90, respectively. Conclusions: Under the same Na concentration, the effects of alkali stress on water content, spectrum, and growth of wheat were stronger than that of salt stress, which was more unfavorable to the growth of wheat. The fusion of low-field nuclear magnetic resonance and MSI technology can improve the classification of wheat stress, and provide an effective technical method for rapid and accurate monitoring of wheat seedlings under saline-alkali stress. [ABSTRACT FROM AUTHOR]

Wheat blast caused by Pyricularia oryzae pathotype Triticum (MoT) has been transmitted from South America to Bangladesh and Zambia and is now spreading in these countries. To prepare against its further spread to Asian countries, we introduced Rmg8, a gene for resistance to wheat blast, into a Japanese elite cultivar, Chikugoizumi (ChI), through recurrent backcrosses and established ChI near-isogenic lines, #2-1-10 with the Rmg8/Rmg8 genotype and #4-2-10 with the rmg8/rmg8 genotype. A molecular analysis suggested that at least 96.6% of the #2-1-10 genome was derived from the recurrent parent ChI. The #2-1-10 line was resistant to MoT not only in primary leaves at the seedling stage but also in spikes and flag leaves at the heading stage. The strength of the resistance in spikes of this Rmg8 carrier was comparable to that of a carrier of the 2NS segment, which has been the only genetic resource released to farmers' fields for wheat blast resistance. On the other hand, the 2NS resistance was not expressed on leaves at the seedling stage nor flag leaves at the heading stage. Considering that leaf blast has been increasingly reported and regarded as an important inoculum source for spike blast, Rmg8 expressed at both the seedling and heading stages, or more strictly in both leaves and spikes, is suggested to be useful to prevent the spread of MoT in Asia and Africa. [ABSTRACT FROM AUTHOR]

Wheat (Triticum spp.) is a primary dietary staple food for humanity. Many wheat genetic resources with variable genomes have a record of domestication history and are widespread throughout the world. To develop elite wheat varieties, agronomical and stress‐responsive trait characterization is foremost for evaluating existing germplasm to promote breeding. However, genomic complexity is one of the primary impediments to trait mining and characterization. Multiple reference genomes and cutting‐edge technologies like haplotype mapping, genomic selection, precise gene editing tools, high‐throughput phenotyping platforms, high‐efficiency genetic transformation systems, and speed‐breeding facilities are transforming wheat functional genomics research to understand the genomic diversity of polyploidy. This review focuses on the research achievements in wheat genomics, the available omics approaches, and bioinformatic resources developed in the past decades. Advances in genomics and system biology approaches are highlighted to circumvent bottlenecks in genomic and phenotypic selection, as well as gene transfer. In addition, we propose conducting precise functional genomic studies and developing sustainable breeding strategies for wheat. These developments in understanding wheat traits have speed up the creation of high‐yielding, stress‐resistant, and nutritionally enhanced wheat varieties, which will help in addressing global food security and agricultural sustainability in the era of climate change. [ABSTRACT FROM AUTHOR]

Breeding wheat cultivars with high nitrogen use efficiency is crucial for sustainable agriculture. In this study, 130 durum wheat accessions from 53 countries were cultivated under two nitrogen fertilization levels to investigate variations in agronomic traits and identify accessions suitable for low-nitrogen conditions. Under no nitrogen fertilization, SPAD value (-99.2), flag leaf length (−15.8 mm), grain area (−0.52 mm² ), grain length (−0.27 mm), thousand-grain weight (+5.2 g), and grain protein content (−4.2%) showed significant differences compared to that under standard nitrogen fertilization. Among these traits, the SPAD value exhibited a strong positive correlation with protein content in the absence of nitrogen fertilization, suggesting its potential as an indicator for selecting germplasm with superior nitrogen use efficiency. Hierarchical cluster analysis, based on the differences in the six traits under the two nitrogen fertilization levels, classified the 130 durum wheat accessions into three groups (Groups 1, 2, and 3). Accessions in Group 2 exhibited superior adaptability under no nitrogen fertilization compared with those in the other two groups. We identified seven accessions in Group 2 that exhibited minimal decreases in SPAD values and protein content under no nitrogen fertilization for use in wheat breeding programs aimed at developing cultivars with high nitrogen use efficiencies. [ABSTRACT FROM AUTHOR]

IDEAL PLANT ARCHITECTURE1 (IPA1) is a pivotal gene controlling plant architecture and grain yield. However, little is known about the effects of Triticum aestivum SQUAMOSA PROMOTER‐BINDING‐LIKE 14 (TaSPL14), an IPA1 ortholog in wheat, on balancing yield traits and its regulatory mechanism in wheat (T. aestivum L.). Here, we determined that the T. aestivum GRAIN WIDTH2 (TaGW2)‐TaSPL14 module influences the balance between tiller number and grain weight in wheat. Overexpression of TaSPL14 resulted in a reduced tiller number and increased grain weight, whereas its knockout had the opposite effect, indicating that TaSPL14 negatively regulates tillering while positively regulating grain weight. We further identified TaGW2 as a novel interacting protein of TaSPL14 and confirmed its ability to mediate the ubiquitination and degradation of TaSPL14. Based on our genetic evidence, TaGW2 acts as a positive regulator of tiller number, in addition to its known role as a negative regulator of grain weight, which is opposite to TaSPL14. Moreover, combinations of TaSPL14‐7A and TaGW2‐6A haplotypes exhibit significantly additive effects on tiller number and grain weight in wheat breeding. Our findings provide insight into how the TaGW2‐TaSPL14 module regulates the trade‐off between tiller number and grain weight and its potential application in improving wheat yield. [ABSTRACT FROM AUTHOR]

Glutaredoxins (GRXs) are widely distributed oxidoreductase enzymes that play important roles in plant growth, development, and responses to various stresses. In this study, bioinformatics methods were used to identify and analyze the wheat GRX gene family and predict their properties and potential functions. RNA-seq and RT-qPCR expression analyses were used to investigate their regulatory functions under hormone treatment and fungal diseases. In this study, 86 GRX genes were identified in wheat and classified into CC-type, CGFS-type, and CPYC-type categories with no TaGRX located on chromosome 4B. The results show that TaGRXs regulate wheat transcriptional responses and have an integrative role in biotic and abiotic stress responses. TaGRXs are involved in wheat responses to Fusarium graminearum, Puccinia striiformis, and Erysiphe graminis diseases. TaGRX73-7D, TaGRX20-3A, and TaGRX29-3B play a negative regulatory role in E. graminis infection but a positive regulatory role in F. graminearum and P. striiformis infection. These TaGRXs play potential regulatory functions in wheat responses to the plant hormones and signaling molecules, including IAA, ABA, H2O2, and SA. The findings of this study lay the groundwork for further investigation of the functions of wheat GRX genes and their potential use as candidate genes for molecular breeding of stress-resistant wheat varieties. [ABSTRACT FROM AUTHOR]

Fertilization significantly affects the growth and development of wheat. However, the precise mechanisms underlying gene regulation during flowering in response to fertilization deficiency remain elusive. In this study, fertilization (F) and non-fertilization (CK)) treatments were set up to reveal examine the effect of fertilization on the photosynthetic capacity of winter wheat during the flowering period through physiological, biochemical, and transcriptome analyses. Upon analyzing analysing their yield, leaf photosynthetic system exchange parameters during flowering, antioxidant enzyme activity, and endogenous hormone parameters, we found that the F treatment resulted in higher net photosynthetic rates during flowering periods than the CK treatment. The superoxide dismutase (SOD) (83.92%), peroxidase (POD) (150.75%), and catalase (CAT) (22.74%) activities of leaves in treated with F during the flowering period were notably elevated compared to those of CK-treated leaves. Abscisic acid (ABA) (1.86%) and gibberellin acid (GA3) (33.69%) levels were reduced, whereas Auxin auxin (IAA) (98.27%) content was increasedwas increased under F treatment compared to those the results under the CK treatment. The chlorophyll a (32.53%), chlorophyll b (56%), total chlorophyll (37.96%), and carotenoid contents (29.80%) under F treatment were also increased compared to CK., exceeded exceeding those obtained under the CK treatment. Furthermore, transcriptional differences between the F and CK conditions were analyzed, and key genes were screened and validated by using q-PCR. Transcriptome analysis identified 2281 differentially expressed genes (DEGs), with enriched pathways related to photosynthesis and light harvesting. DEGs were subjected to cluster simulation, which revealed that 53 DEGS, both up- and down-regulated, responded to the F treatment. qRT-PCR-based validation confirmed the differential expression of genes associated with carbohydrate transport and metabolism, lipid transport, and signal transduction. This study revealed distinctive transcriptional patterns and crucial gene regulation networks in wheat during flowering under fertilization, providing transcriptomic guidance for the precise regulation of wheat breeding. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is a crucial cereal crop, contributing around 20% of global caloric intake. However, challenges such as diminishing arable land, water shortages, and climate change threaten wheat production, making yield enhancement crucial for global food security. The heading date (HD) is a critical factor influencing wheat's growth cycle, harvest timing, climate adaptability, and yield. Understanding the genetic determinants of HD is essential for developing high-yield and stable wheat varieties. This study used a doubled haploid (DH) population from a cross between Jinmai 47 and Jinmai 84. QTL analysis of HD was performed under three phosphorus (P) treatments (low, medium, and normal) across six environments, using Wheat15K high-density SNP technology. The study identified 39 QTLs for HD, distributed across ten chromosomes, accounting for 2.39% to 29.52% of the phenotypic variance. Notably, five stable and major QTLs (Qhd.saw-3A.7, Qhd.saw-3A.8, Qhd.saw-3A.9, Qhd.saw-4A.4, and Qhd.saw-4D.3) were consistently detected across varying P conditions. The additive effects of these major QTLs showed that favorable alleles significantly delayed HD. There was a clear trend of increasing HD delay as the number of favorable alleles increased. Among them, Qhd.saw-3A.8, Qhd.saw-3A.9, and Qhd.saw-4D.3 were identified as novel QTLs with no prior reports of HD QTLs/genes in their respective intervals. Candidate gene analysis highlighted seven highly expressed genes related to Ca2+ transport, hormone signaling, glycosylation, and zinc finger proteins, likely involved in HD regulation. This research elucidates the genetic basis of wheat HD under P stress, providing critical insights for breeding high-yield, stable wheat varieties suited to low-P environments. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB), caused by the Fusarium graminearum species complex, is a destructive disease in wheat worldwide. The lack of FHB-resistant germplasm is a barrier in wheat breeding for resistance to FHB. Thinopyrum elongatum is an important relative that has been successfully used for the genetic improvement of wheat. In this study, a translocation line, YNM158, with the YM158 genetic background carrying a fragment of diploid Th. elongatum 7EL chromosome created using 60Co-γ radiation, showed high resistance to FHB under both field and greenhouse conditions. Transcriptome analysis confirmed that the horizontal transfer gene, encoding glutathione S-transferase (GST), is an important contributor to FHB resistance in the pathogen infection stage, whereas the 7EL chromosome fragment carries other genes regulated by F. graminearum during the colonization stage. Introgression of the 7EL fragment affected the expression of wheat genes that were enriched in resistance pathways, including the phosphatidylinositol signaling system, protein processing in the endoplasmic reticulum, plant–pathogen interaction, and the mitogen-activated protein kinase (MAPK) signaling pathway at different stages after F. graminearium infection. This study provides a novel germplasm for wheat resistance to FHB and new insights into the molecular mechanisms of wheat resistance to FHB. [ABSTRACT FROM AUTHOR]

Eukaryotic gene transcription is fine-tuned by precise spatiotemporal interactions between cis-regulatory elements (CREs) and trans-acting factors. However, how CREs individually or coordinated with epigenetic marks function in regulating homoeolog bias expression is still largely unknown in wheat. In this study, through comprehensively characterizing open chromatin coupled with DNA methylation in the seedling and spikelet of common wheat, we observed that differential chromatin openness occurred between the seedling and spikelet, which plays important roles in tissue development through regulating the expression of related genes or through the transcription factor (TF)-centered regulatory network. Moreover, we found that CHH methylation may act as a key determinant affecting the differential binding of TFs, thereby resulting in differential expression of target genes. In addition, we found that sequence variations in MNase hypersensitive sites (MHSs) result in the differential expression of key genes responsible for important agronomic traits. Thus, our study provides new insights into the roles of CREs in regulating tissue or homoeolog bias expression, and controlling important agronomic traits in common wheat. It also provides potential CREs for genetic and epigenetic manipulation toward improving desirable traits for wheat molecule breeding. [ABSTRACT FROM AUTHOR]

Summary: Drought, especially terminal drought, severely limits wheat growth and yield. Understanding the complex mechanisms behind the drought response in wheat is essential for developing drought‐resistant varieties. This study aimed to dissect the genetic architecture and high‐yielding wheat ideotypes under terminal drought.An automated high‐throughput phenotyping platform was used to examine 28 392 image‐based digital traits (i‐traits) under different drought conditions during the flowering stage of a natural wheat population. Of the i‐traits examined, 17 073 were identified as drought‐related. A genome‐wide association study (GWAS) identified 5320 drought‐related significant single‐nucleotide polymorphisms (SNPs) and 27 SNP clusters.A notable hotspot region controlling wheat drought tolerance was discovered, in which TaPP2C6 was shown to be an important negative regulator of the drought response. The tapp2c6 knockout lines exhibited enhanced drought resistance without a yield penalty. A haplotype analysis revealed a favored allele of TaPP2C6 that was significantly correlated with drought resistance, affirming its potential value in wheat breeding programs.We developed an advanced prediction model for wheat yield and drought resistance using 24 i‐traits analyzed by machine learning. In summary, this study provides comprehensive insights into the high‐yielding ideotype and an approach for the rapid breeding of drought‐resistant wheat. [ABSTRACT FROM AUTHOR]

Tan spot disease of wheat (also known as yellow spot) is caused by the necrotrophic fungal pathogen Pyrenophora tritici‐repentis (Ptr). Initially described as a grass pathogen, Ptr has become a wheat pathogen of global importance. In Australia, tan spot was first recorded in 1952 as a minor wheat disease. However, by the 1970s tan spot had reached epidemic levels in Australia with yield losses of up to 49% reported in the north‐eastern region. A national survey carried out in 2007/2008 placed tan spot as the most economically important wheat disease with an estimated yield loss of 6%, corresponding to nearly a quarter of all disease losses. The incidence of tan spot in Australia has now markedly reduced with some wheat breeding programmes no longer considering tan spot disease resistance to be a priority trait. The disease can be effectively managed with integrated control strategies such as crop rotation, timely application of fungicides and removal of surface stubble. However, the key to the success of controlling tan spot disease in Australia has been achieved through wheat breeding programmes. The development of tan spot resistance resources suitable for the Australian climate was a concerted effort between national and international research organizations and Australian wheat breeders, supported by the Australian Grains Research Development Corporation (GRDC). While traditional breeding was essential to combat the disease, this article highlights the value of effector biology in assisting the development of resistant cultivars. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the optimal irrigation needs of six popular Egyptian bread wheat (Triticum aestivum L.) cultivars and to establish baseline effect of reduced irrigation on yield. The varieties included were Sids1, Sids14, Sakha94, Sakha95, Gemmiza12, and Shandawee1. The experiment was conducted at two different locations, Nubaria and Sids Agricultural Research Stations, Egypt over two consecutive seasons, 2020–2021 and 2021–2022. There was a reduction in yield with the decrease in the number of irrigations. However, several cultivars performed better for yield and other traits with one less irrigation than the current irrigation practices in the region. Therefore, the study may help revise irrigation recommendations. Overall, the cultivars Sakha95, Sids1, and Sids14 were taller and had more kernels per spike, higher seed index, and greater grain yield under reduced irrigations and showed the best drought tolerance index. The tested bread wheat cultivars were genotyped using Inter-Retrotransposon Amplified Polymorphism (IRAP) and Start Codon Targeted (SCoT) markers which showed relation among the cultivars. Among the two types of markers, IRAP was better than SCoT markers for reliability and robustness. Among the six cultivars, 58% of the IRAP markers detected polymorphism as compared to 38% with SCoT markers. The two wheat cultivars Sids1 and Sids14, which performed better for important agronomic traits under water stress conditions, could be used as donors for the national wheat breeding program for drought tolerance. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Increasing crop productivity is often proposed as a key goal for meeting the food security demands of a growing global population. However, achieving high crop yields alone without meeting end‐use quality requirements is counter to this objective and can lead to negative environmental and sustainability issues. High yielding feed wheat crops in the United Kingdom are a typical example of this. The historical context of UK agricultural industrialisation, developments in plant breeding and wheat end‐use processing are examined. We then outline how employing innovations in plant breeding methods offer the potential to redress the balance between wheat quantity and quality. Summary: Bread wheat (Triticum aestivum L.) has historically been an important crop for many human civilisations. Today, variability in wheat supply and trade has a large influence on global economies and food security. The United Kingdom is an example of an industrialised country that achieves high wheat yields through intensive cropping systems and a favourable climate. However, only a minority of the wheat grain produced is of suitable end‐use quality for modern bread baking methods and most wheat produced is fed to livestock. A large agricultural land area and input use dedicated to producing grain for animal rather than human food has wide‐ranging negative impacts for environmental sustainability and domestic food production. Here we present an historical perspective of agricultural and economic changes that have resulted in UK production primarily focussing on wheat quantity over quality. Agricultural intensification, liberalisation of free trade in agricultural commodities, innovations in the milling and baking sector, developments in scientific understanding of genetics and plant breeding, and geopolitical changes have all played a role. We propose that wheat breeding plays a crucial role in influencing these issues and although wheat breeders in the United Kingdom have historically applied the most‐up‐to‐date scientific advances, recent advances in genomics tools and quantitative genetics present a unique opportunity for breeders to redress the balance between quantity and quality. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: The Green Revolution is commonly understood as the dramatic increase in food production in Mexico and India between the 1940s and 1970s due to the spread of new agricultural technologies, especially high‐yielding seed varieties. Beyond this conventional understanding, however, historians are now revealing the occurrence of—and connections between—various Green Revolutions across space and time. This article identifies a "fascist Green Revolution" through the history of agrarian development and scientific wheat breeding in fascist Italy (1922–1943). Through this case study, the article provides new insights into key themes of discussion around the Green Revolution such as the relationship between plant breeding, the environment, food security, and food self‐sufficiency. Summary: In 1925, the fascist regime launched the "Battle of Wheat," a plan of agrarian development aimed at achieving self‐sufficiency in wheat, Italy's main food crop. Key to this project was the replacement of traditional landraces with "elite" semi‐dwarf and early‐maturing wheat cultivars released by Italy's star plant breeder Nazareno Strampelli. Through the historical analysis of Strampelli's breeding program and of the implementation of the fascist "seed replacement" strategy, this article makes the case for viewing the Battle of Wheat as a "fascist Green Revolution."The article draws on new methods and perspectives developed by the historiography of the Green Revolution. It is grounded on the historical analysis of fascist‐era publications and archival documents produced by Italian crop scientists and agricultural research institutions.While "elite" cultivars spread rapidly in fertile and wealthy northern Italy, they struggled to take hold in the dry and poor Italian South. The article delineates the environmental, social, and economic reasons underpinning this divergence. Focusing in particular on agrarian scientists' approaches to crop improvement in the Italian South, the article shows how this "marginal" region became a key site for the development of scientific counter‐narratives and concrete alternatives to the official fascist strategy of "seed replacement."The article reveals the co‐existence of multiple approaches over space and time within fascist‐era agrarian science. Through this case study, it provides new elements to analyze key themes in science and agriculture historiography such as the tension between hyper‐modernization and agroecological concerns, centralized and decentralized research, imported technologies and local resources. [ABSTRACT FROM AUTHOR]

Wheat, a staple cereal crop, faces challenges due to climate change and increasing global population. Maintaining genetic diversity is vital for developing drought-tolerant cultivars. This study evaluated the genetic diversity and drought response of five wheat cultivars and their corresponding F1 hybrids under well-watered and drought stress conditions. Molecular profiling using ISSR and SCoT-PCR markers revealed 28 polymorphic loci out of 76 amplified. A statistically significant impact of parental genotypes and their crosses was observed on all investigated agro-morphological traits, including root length, root weight, shoot length, shoot weight, proline content, spikelet number/spike, spike length, grain number/spike, and grain weight/spike. The parental genotypes P1 and P3 had desirable positive and significant general combining ability (GCA) effects for shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, shoot length, and root length under well-watered conditions, while P3 and P5 recorded the highest GCA estimates under drought stress. P3 and P4 showed the highest GCA effects for number of spikelets per spike, the number of grains per spike, and grain weight per spike under normal conditions. P5 presented the maximum GCA effects and proved to be the best combiner under drought stress conditions. The cross P1× P3 showed the highest positive specific combining ability (SCA) effects for shoot fresh weight under normal conditions, while P2×P3 excelled under water deficit conditions. P1× P2, P1 × P3, and P4× P5 were most effective for shoot dry weight under normal conditions, whereas P1×P3 and P3×P5 showed significant SCA effects under drought stress. Positive SCA effects for root fresh weight and shoot length were observed for P3×P5 under stressed conditions. Additionally, P4×P5 consistently recorded the highest SCA for root length in both environments, and P3×P5 excelled in the number of spikelets, grains per spike, and grain weight per spike under drought conditions. The evaluated genotypes were categorized based on their agronomic performance under drought stress into distinct groups ranging from drought-tolerant genotypes (group A) to drought-sensitive ones (group C). The genotypes P5, P2×P5, and P3×P5 were identified as promising genotypes to improve agronomic performance under water deficit conditions. The results demonstrated genetic variations for drought tolerance and highlighted the potential of ISSR and SCoT markers in wheat breeding programs for developing drought-tolerant cultivars. [ABSTRACT FROM AUTHOR]

Background: Seed vigor recognized as a quantitative trait is of particular importance for agricultural production. However, limited knowledge is available for understanding genetic basis of wheat seed vigor. Methods: The aim of this study was to identify quantitative trait loci (QTL) responsible for 10 seed vigor-related traits representing multiple aspects of seed-vigor dynamics during artificial aging with 6 different treatment times (0, 24, 36, 48, 60, and 72 h) under controlled conditions (48 °C, 95% humidity, and dark). The mapping populations were two wheat introgression lines (IL-1 and IL-2) derived from recipient parent (Lumai 14) and donor parent (Shaanhan 8675 or Jing 411). Results: A total of 26 additive QTLs and 72 pairs of epistatic QTLs were detected for wheat seed-vigor traits. Importantly, chromosomes 1B and 7B contained several co-located QTLs, and chromosome 2A had a QTL-rich region near the marker Xwmc667, indicating that these QTLs may affect wheat seed vigor with pleiotropic effects. Furthermore, several possible consistent QTLs (hot-spot regions) were examined by comparison analysis of QTLs detected in this study and reported previously. Finally, a set of candidate genes for wheat seed vigor were predicted to be involved in transcription regulation, carbohydrate and lipid metabolism. Conclusion: The present findings lay new insights into the mechanism underlying wheat seed vigor, providing valuable information for wheat genetic improvement especially marker-assisted breeding to increase seed vigor and consequently achieve high grain yield despite of further investigation required. [ABSTRACT FROM AUTHOR]

Arabinoxylan (AX) and resistant starch (RS) are essential components of dietary fiber, that affect the nutritional value, health benefits, and end-use quality of wheat. Fully understanding their genetic basis is crucial for enhancing wheat quality through marker-assisted selection or other means. In this study, a genome-wide association study of AX-related traits i.e., total-arabinoxylan (TAX), water-extractable arabinoxylan (WEAX), and water un-extractable arabinoxylan (WUAX) of whole wheat flour (WWF) and refined wheat flour (RWF), as well as RS content was conducted using 205 elite wheat varieties (lines) with a composite map (24,355 SNPs) constructed with 90 K single nucleotide polymorphism (SNP) arrays. The broad-sense heritability (H2) of RS was 48.50%, whereas that of AX-related traits ranged from 55.66 to 77.23%. A total of 115 loci for RS and AX related traits, comprising 322 marker-trait associations (MTAs), were identified on all 21 chromosomes across four environments, explaining 5.52–12.40% of the phenotypic variance. Among them, 19 stable loci were significant in two or more environments, including one for RWF-TAX, six for RWF-WEAX, four for RWF-WUAX, three for WWF-TAX, two for WWF-WUAX, and three for RS. Furthermore, 17 co-located chromosomal regions related to the measured traits were stably detected in multiple environments. These findings may be used for further research and to improve wheat quality in wheat breeding programs. [ABSTRACT FROM AUTHOR]

The nitrogen (N) use efficiency (NUE) in the roots of seedlings is beneficial for increasing crop yield. Creating marker-assisted selection for wheat root traits can assist wheat breeders in choosing robust roots to maximize nutrient uptake. Exploring and identifying the effect of different N supply conditions on root system architecture (RSA) is of great significance for breeding N efficient wheat varieties. In this study, a total of 243 wheat varieties native to the Yellow and Huai Valley regions of China were utilized for genome-wide association studies (GWAS). Furthermore, a recombinant inbred line (RIL) population of 123 lines derived from the cross between Avocet and Chilero was utilized for linkage examination. A hydroponic seedling experiment using a 96-well tray was conducted in the lab with two treatments: normal N (NN) and low N (LN). Five RSA traits, including the relative number of root tips (RNRT), relative total root length (RTRL), relative total root surface area (RTRS), relative total root volume (RTRV), and relative average root diameter (RARD), were investigated. GWAS and linkage analysis were performed by integrating data from the wheat 660 k single nucleotide polymorphism (SNP) chip and diversity arrays technology (DArT) to identify genetic loci associated with RSA. The results showed that, based on the ratio of RSA-related traits under two N supply conditions, a total of 497 SNP markers, which are significantly associated with RSA-related traits, were detected at 148 genetic loci by GWAS. A total of 10 QTL loci related to RSA were discovered and identified by linkage mapping. Combining two gene localization methods, three colocalized intervals were found: AX-95160997/QRtrl.haust-3D, AX-109592379/QRnrt.haust-5A, and AX-110924288/QRtrl.haust-7D/QRtrs.haust-7D. According to the physical location of the colocalization of these two sites, between 39.61 and 43.74 Mb, 649.97 and 661.55 Mb, and 592.44 and 605.36 Mb are called qRtrl-3D, qRnrt-5A, and qRtrl-7D. This study has the potential to enhance the effectiveness of selecting root traits in wheat breeding programs, offering valuable insights into the genetic underpinnings of NUE in wheat. These results could help in breeding wheat varieties with higher NUE by implementing focused breeding strategies. [ABSTRACT FROM AUTHOR]

Common wheat is one of the most important food crops in the world. Grain harvests can be increased by reducing losses from diseases and environmental stresses. The tertiary gene pool, including Thinopyrum spp., is a valuable resource for increasing genetic diversity and wheat resistance to fungal diseases and abiotic stresses. Distant hybridization between wheat and Thinopyrum spp. began in the 1920s in Russia, and later continued in different countries. The main results were obtained using the species Th. ponticum and Th. intermedium. Additionally, introgression material was created based on Th. elongatum, Th. bessarabicum, Th. junceiforme, Agropyron cristatum. The results of introgression for resistance to diseases (leaf, stem, and stripe rusts; powdery mildew; Fusarium head blight; and Septoria blotch) and abiotic stresses (drought, extreme temperatures, and salinity) to wheat was reviewed. Approaches to improving the agronomic properties of introgression breeding material (the use of irradiation, ph-mutants and compensating Robertsonian translocations) were described. The experience of long-term use in the world of a number of genes from the tertiary gene pool in protecting wheat from leaf and stem rust was observed. Th. ponticum is a nonhost for Puccinia triticina (Ptr) and P. graminis f. sp. tritici (Pgt) and suppresses the development of rust fungi on the plant surface. Wheat samples with the tall wheatgrass genes Lr19, Lr38, Sr24, Sr25 and Sr26 showed defence mechanisms similar to nonhosts resistance. Their influence led to disruption of the development of surface infection structures and fungal death when trying to penetrate the stomata (prehaustorial resistance or stomatal immunity). Obviously, a change in the chemical properties of fungal surface structures of races virulent to Lr19, Lr24, Sr24, Sr25, and Sr26 leads to a decrease in their adaptability to the environment. This possibly determined the durable resistance of cultivars to leaf and stem rusts in different regions. Alien genes with a similar effect are of interest for breeding cultivars with durable resistance to rust diseases and engineering crops with the help of molecular technologies.

Key message: A major stable QTL, QGPC.caas-7AL, for grain protein content of wheat, was narrowed down to a 1.82-Mb inter on chromosome 7AL, and four candidate genes were predicated. Wheat grain protein content (GPC) is important for end-use quality. Identification of genetic loci for GPC is helpful to create new varieties with good processing quality and nutrients. Zhongmai 578 (ZM578) and Jimai 22 (JM22) are two elite wheat varieties with different contents of GPC. In the present study, 262 recombinant inbred lines (RILs) derived from a cross between ZM578 and JM22 were used to map the GPC with high-density wheat Illumina iSelect 50 K single-nucleotide polymorphism (SNP) array. Seven quantitative trait loci (QTLs) were identified for GPC on chromosomes 3AS, 3AL, 3BS, 4AL, 5BS, 5DL and 7AL by inclusive composite interval mapping, designated as QGPC.caas-3AS, QGPC.caas-3AL, QGPC.caas-3BS, QGPC.caas-4AL, QGPC.caas-5BS, QGPC.caas-5DL and QGPC.caas-7AL, respectively. Among these, alleles for increasing GPC at QGPC.caas-3AS, QGPC.caas-3BS, QGPC.caas-4AL and QGPC.caas-7AL loci were contributed by ZM578, whereas those at the other three loci were from JM22. The stable QTL QGPC.caas-7AL was fine mapped to a 1.82-Mb physical interval using secondary populations from six heterozygous recombinant plants obtained by selfing a residual RIL. Four genes were predicted as candidates of QGPC.caas-7AL based on sequence polymorphism and expression patterns. The near-isogenic lines (NILs) with the favorable allele at the QGPC.caas-7AL locus increased Farinograph stability time, Extensograph extension area, extensibility and maximum resistance by 19.6%, 6.3%, 6.0% and 20.3%, respectively. Kompetitive allele-specific PCR (KASP) marker for QGPC.caas-7AL was developed and validated in a diverse panel of 166 Chinese wheat cultivars. These results provide further insight into the genetic basis of GPC, and the fine-mapped QGPC.caas-7AL will be an attractive target for map-based cloning and marker-assisted selection in wheat breeding programs. [ABSTRACT FROM AUTHOR]

Over the past century, environmental changes have significantly impacted wheat spike morphology, crucial for adaptation and grain yield. However, the changes in wheat spike modifications during this period remain largely unknown. This study examines 16 spike morphology traits in 830 accessions released from 1900 to 2020. It finds that spike weight, grain number per spike (GN), and thousand kernel weight have significantly increased, while spike length has no significant change. The increase in fertile spikelets is due to fewer degenerated spikelets, resulting in a higher GN. Genome‐wide association studies identified 49,994 significant SNPs, grouped into 293 genomic regions. The accumulation of favorable alleles in these genomic regions indicates the genetic basis for modification in spike morphology traits. Genetic network analysis of these genomic regions reveals the genetic basis for phenotypic correlations among spike morphology traits. The haplotypes of the identified genomic regions display obvious geographical differentiation in global accessions and environmental adaptation over the past 120 years. In summary, we reveal the genetic basis of adaptive evolution and the interactions of spike morphology, offering valuable resources for the genetic improvement of spike morphology to enhance environmental adaptation. Summary statement: In this study, we investigated the genetic basis of changes in spike morphology during wheat breeding. We identified candidate regions responsible for consistent alterations in spike morphology traits that led to increased yield. Furthermore, we constructed a genetic network of related genomic regions. Our findings unveil the genetic underpinnings of breeding selection and the interplay of spike morphology traits, offering valuable resources for the regulation of spike morphology in wheat. [ABSTRACT FROM AUTHOR]

Worldwide food security is severely threatened by the devastating wheat stripe rust disease. The utilization of resistant wheat cultivars represents the most cost‐effective and efficient strategy for combating this disease. However, the lack of resistant resources has been a major bottleneck in breeding for wheat disease resistance. Therefore, revealing novel gene resources for combating stripe rust and elucidating the underlying resistance mechanism is of utmost urgency. In this study, we identified that the soybean NF‐YB transcription factor GmNF‐YB20 in wheat provides resistance to the stripe rust fungus (Puccinia striiformis f. sp. tritici, Pst). Wheat lines with stable overexpression of the GmNF‐YB20 enhanced resistance against multiple Pst races. Transcriptome profiling of GmNF‐YB20 transgenic wheat under Pst infection unveiled its involvement in the lipid signaling pathway. RT‐qPCR assays suggested that GmNF‐YB20 increased transcript levels of multiple nonspecific lipid transfer protein (LTP) genes during wheat‐Pst interaction, luciferase reporter analysis illustrates that it activates the transcription of TaLTP1.50 in wheat protoplast, and GmNF‐YB20 overexpressed wheat plants had higher total LTP content in vivo during Pst infection. Overexpression of TaLTP1.50 in wheat significantly increased resistance to Pst, whereas knockdown of TaLTP1.50 exhibited the opposite trends, indicating that TaLTP1.50 plays a positive role in wheat resistance. Taken together, our findings provide perspective regarding the molecular mechanism of GmNF‐YB20 in wheat and highlight the potential use for wheat breeding. Summary statement: The soybean transcription factor GmNF‐YB20 confers resistance to stripe rust in transgenic wheat by regulating nonspecific lipid transfer protein genes. Our findings provide perspective regarding the molecular mechanism of GmNF‐YB20 in wheat and highlight the potential use for wheat breeding. [ABSTRACT FROM AUTHOR]

Exposing genetic material with physical mutagens can create novel genetic resources capable of combating different stresses. High throughput GBS-DArTseq™ assay was deployed to estimate genetic diversity of 33 newly developed stable wheat mutants as compared to the wild type. The identified 1,57,608 PAVs markers were randomly distributed across wheat chromosomes and sub-genomes with the highest number detected on Chr-7D (2877) and Chr-7B (2711). The B sub-genome contained the most PAVs followed by D and A-sub genome. Among mutant lines, Pb-M-2061 and Pb-M-59 had the highest PAV count, while Pb-M-605 and Pb-M-196 had the lowest. A total of 7,910 PAVs were consistently present over all replicates, with 3,252 specifically present in mutants and absent in wild type. The maximum PAVs (1480) were found in Pb-M-1027 and Pb-M-1323 (656). Functional characterization revealed that out of 3,252, 1,238 were found in wheat transcriptome database that contained 152 characterized and 1,196 uncharacterized genes. COGs and GO-terms analysis linked many PAVs with pathways involving signaling, metabolism and defense. Maximum number of gene-containing PAVs were identified in Pb-M-1027, Pb-M-2302 and Pb-M-1323 which were involved in tolerance to diseases and abiotic stresses, improved photosynthetic efficiency, larger grain size, increased grain yield and harvest index pathways. This study provides valuable insights into the genetic diversity and potential agronomic benefits of PAVs in wheat mutant lines. These findings can help molecular geneticist and breeders for exploiting the induced genetic diversity for unravelling the genetic circuits as well as exploiting in wheat breeding for developing resilient cultivars. [ABSTRACT FROM AUTHOR]